1. Field of the Invention
The present invention relates to methods for manufacturing ceramic electronic components such as multilayer capacitors, and more specifically, to a method for manufacturing a ceramic electronic component including an improved gravure-printing step in which conductive paste is printed on a ceramic green sheet.
2. Description of the Related Art
In a manufacturing process of, for example, a multilayer ceramic capacitor, a gravure-printing method is used for printing ceramic paste and conductive paste on a ceramic green sheet disposed on a supporting film.
Japanese Unexamined Patent Application Publication No. 8-250370 discloses a method for manufacturing a multilayer ceramic capacitor in which a plurality of internal electrode patterns are formed on a dielectric green sheet disposed on a long supporting film by gravure printing using a first gravure roll and a step-reducing dielectric pattern is formed so as to fill the spaces between the internal electrode patterns by gravure printing using a second gravure roll.
In the above-described method in which the internal electrode patterns and the step-reducing dielectric pattern are formed on the long dielectric green sheet using the gravure rolls, displacement along the width of the dielectric green sheet (displacement in a direction perpendicular to the conveying direction of the dielectric green sheet) often occurs.
In the case in which the internal electrode patterns and the step-reducing dielectric pattern are printed on the dielectric green sheet as described above, when the displacement along the width of the dielectric green sheet occurs, the internal electrode patterns and the step-reducing dielectric pattern are not formed at desired locations since the internal electrode patterns and the step-reducing dielectric pattern overlap each other or intervals between them are excessively increased.
Therefore, the displacement along the width of the dielectric green sheet is corrected before the second gravure-printing step by moving the second gravure roll along its axis, that is, along the width of the dielectric green sheet.
Therefore, as shown in FIG. 17, a distorted step-reducing dielectric pattern 101b is produced depending on the timing of the movement of the gravure roll. With reference to FIG. 17, a long dielectric green sheet 102 is disposed on a supporting film, and the supporting film is conveyed in a direction shown by the arrow A. In addition, a print direction is shown by the arrow B, and a position at which the gravure roll is moved is denoted by C. Each of print patterns 101a, 101b, and 101c is printed by a single turn of the gravure roll.
In addition, there is also a problem in that the thickness of the step-reducing dielectric pattern 101b changes depending on the time at which the gravure roll is moved.
When the distortion and the change in thickness of the step-reducing dielectric pattern occur as described above, the step-reducing dielectric pattern does not provide its intended purpose, which is to eliminate the steps around the internal electrode patterns, and structural defects of the laminate such as delamination may occur.
In addition, similar to the above-described gravure-printing method for printing the conductive paste and the step-reducing ceramic paste in the process of manufacturing the multilayer ceramic capacitor, a multicolor gravure-printing method also has a problem in that a displacement occurs and high-definition multicolor printing is difficult.